How to Perform a Wi-Fi Site Survey and Why?

What are the different types of Wi-Fi on-site surveys, when to use them, and how to conduct them effectively? We recently held a webinar series covering basic Wi-Fi technology concepts as well as the tools used in wireless throughout the lifecycle. 

In this post, we’ll summarize the fourth episode of the webinar series, hosted by Jerry Olla: How (and why) to perform a Wi-Fi site survey. 

Watch webinar recording

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Types of Wi-Fi Site Surveys

Site surveys aren't one-size-fits-all solutions. Understanding the different types helps you choose the right approach for your specific needs and budget constraints. 

Pre-Deployment Site Surveys involve physically walking around the site before installing equipment to capture existing conditions. Modern tools can leverage this data to calibrate design models and identify coverage gaps, interference sources, and potential issues. 

Post-Deployment Site Surveys validate whether your implemented network meets requirements. They confirm equipment installation accuracy, verify correct configurations, and identify malfunctioning hardware. 

When forced to choose between pre- and post-deployment surveys due to budget constraints, post-deployment surveys often take priority. 

AP-on-a-Stick Surveys involve temporarily mounting planned access points on portable tripods to validate simulations. While extremely detailed, they're very time-consuming. Modern simulation software has improved dramatically, reducing the necessity for AP-on-a-stick surveys in standard office environments. 

Predictive Surveys - This terminology creates confusion because it doesn't involve actual on-site work. What's commonly called a "predictive survey" is more accurately described as a "predictive design" or "simulated model.”

Passive Surveys

Passive Surveys are a method of collecting Wi-Fi signal data without actively connecting to or interacting with the wireless network. During the survey, a measurement device (Ex. Oscium Nomad) listens to information about nearby Wi-Fi access points (APs) and their signals, including signal strength, channel, SSID, and other parameters, without transmitting any data or associating with the network.

Key Characteristics:

• Non-intrusive: The surveying device remains silent, only receiving broadcasted signals (e.g., beacons) from APs.
• Data Collection: Captures details like signal strength (RSSI), noise levels, channel usage, and AP locations.
• Use Cases: Commonly used for assessing Wi-Fi coverage, identifying interference, planning network deployments, or troubleshooting performance issues.

Active Surveys

Active Surveys focus on performance validation by associating client devices with the network and testing throughput, latency, packet loss, and roaming behavior. They're valuable for critical applications like voice over Wi-Fi, but tend to be optional for most deployments. The challenge is inconsistency - results can vary dramatically based on timing and environmental factors. 

Key Characteristics

• Active Connection: The surveying device associates with the Wi-Fi network, authenticating and connecting to access points (APs) to measure real-world performance.
• Performance Metrics: Collects detailed data such as:
  • Throughput: Upload and download speeds.
  • Latency: Response times for data packets.
  • Packet Loss: Dropped packets during transmission.
  • Connection Stability: Assesses how reliably the device stays connected.
• Real-Time Testing: The device actively sends and receives data, simulating user activity to evaluate network performance under load.
• Network-Specific: Requires credentials (e.g., SSID and password) to connect to the target network, making it specific to the network being tested.

Survey Tools 

The Hamina solution combines the Hamina Onsite mobile application (iPhone/iPad) with the Oscium Nomad Wi-Fi measurement device. The mobile app syncs with Hamina Network Planner in the cloud, enabling surveys even without internet connectivity. 

The Oscium Nomad is a thin, lightweight device worn with a shoulder strap. When surveying, it is important understand how the position of the Nomad can impact the results - for example, if you are validating for a mobile device, positioning the device chest height typically provides the most representative measurements.

Survey Modes

Continuous Survey Mode collects maximum data in minimum time. You tap the screen when you start walking, stop, and change directions. Requires staying alert, especially in busy environments. 

Line Survey Mode provides breathing room between segments. When you reach a turn or stopping point, the survey ends that segment, giving you time to reorient and plan your next path. More forgiving for newcomers. 

Point Survey Mode takes precise measurements at specific locations. Very accurate but extremely time-consuming - typically takes two to three times longer than other methods. 

For more realistic data, it is recommended to conduct the survey during typical usage hours. With continuous and line survey modes it is also important to maintain a consistent pace throughout each survey segments and remember to tap when you start walking, stop walking and change directions.

Hamina Onsite allows you to easily switch between different survey modes.

Identifying Common Post-Deployment Issues

Site surveys excel at identifying several categories of problems that can impact network performance. These include, for example: 

• Coverage Gaps: Areas with low or no signal strength where users might experience poor connectivity. 

• Interference Sources: Co-channel and adjacent channel interference from your own access points, neighboring networks, or rogue devices. 
• Performance Issues: Areas with low throughput, high latency, or excessive packet loss. 
• Rogue Access Points: Unauthorized or unintentional access points that might represent security concerns or impact network performance. 

Advanced Survey Capabilities

Modern survey tools offer additional capabilities beyond basic RF measurement, such as: 

• Spectrum Analysis: Optional spectrum analyzer modules can identify non-Wi-Fi interference sources in the environment. 

• Live Troubleshooting: Real-time views of network conditions for immediate troubleshooting.

• Integration with Network Management: Modern survey tools integrate with cloud management platforms from major vendors like Cisco, Juniper, Aruba, and others.

Hamina Live, part of the Network Planner Plus subscription, allows you to monitor the live status of your APs as well as each client connected to your APs. Integrates with leading Wi-Fi cloud vendors.

Analyzing and Optimizing Results

Once survey data is collected, several analysis and optimization options become available: 

• Coverage Analysis: Basic coverage analysis involves reviewing signal strength patterns and identifying areas that don't meet minimum requirements. 

• Design Calibration: Advanced tools can use survey data to calibrate simulation models for more accurate predictions. 
• Remediation Planning: Survey data informs whether simple configuration changes will solve problems or whether more significant changes like moving or adding equipment are necessary. 

Key Takeaways

Site surveys remain critical for successful wireless deployments. While modern simulation tools have reduced the necessity for some traditional survey methods, post-deployment validation continues to be essential. 

For most deployments, passive surveys provide the essential validation data needed, while active surveys serve specific use cases requiring application-level performance validation. The key is matching your survey approach to your specific validation needs while maintaining efficient use of time and resources.